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Re: [Fwd: When The Asteroid Hit, Most Plant-Eating Bugs Died]



Kurtis Law wrote:
 
> Here is an interesting e-mail I received from NASA , so tell me your 
> thoughts.  If
> true, then surviving plants had little predation from insects to worry about. 
>  But
> how about those animals whom are herbivores, wouldn't this mean less 
> competition
> for them, and more herbivore action on the surviving vegetation given the 
> reduced
> food supply?  None the less it is interesting to think about, particularly 
> when you
> try to understand relationships Between various plants and animals in a now 
> extinct
> environment.

Studies around Mount St.Helens showed that devastated areas were first
re-colonised by a strictly carnivorous arthropod ecosystem (mainly
spiders eating other spiders). Then plants began to regrow (beginning
with ferns - a modern fern spike!). If the arthropod carnivores were
able to sustain themselves long enough to see plant regrowth, perhaps it
took a while for herbivorous insects to re-colonise, given the large
amount of carnivores already established?

Of course, the area around Mount St.Helens was fairly localised, so
wind-blown insects may have helped feed the carnivorous arthropods. I
wonder if such a strictly carnivorous ecosystem would be sustainable if
a much larger area was devastated (on the continental or even global
scale)?

-- 
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Dann Pigdon                   Australian Dinosaurs:
GIS Archaeologist           http://www.geocities.com/dannsdinosaurs
Melbourne, Australia        http://www.alphalink.com.au/~dannj/
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